import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 23735
 * Date: 2022-09-25
 * Time: 22:30
 */
public class TestDemo1 {
        public static void main(String[] args) {

            Scanner scanner=new Scanner(System.in);

            while(scanner.hasNextLine()){
                StringBuilder sb=new StringBuilder();
                String str= scanner.nextLine();
                int [] arr=new int[58];
                for(int i=0;i<str.length();i++){
                    char ch=str.charAt(i);
                    //方法一
                    //直接判断sb中是否含有该字符
                    //if(!sb.toString().contains(ch+"")){
                    //sb.append(ch);
                    //}

                    //方法二
                    //类似于哈希表判断是否添加过该字符
                    if(arr[ch-65]==0){
                        sb.append(ch);
                        arr[ch-65]++;
                    }
                }
                System.out.println(sb);
            }
        }
}
